Fixing apparatus and image forming apparatus including the same

Abstract

A fixing apparatus of the present invention includes a fixing rotation member, a rotation drive portion that rotates the fixing rotation member, a cleaning web sheet that cleans a circumferential surface of the fixing rotation member, a cleaning web sheet roller that takes up or feeds out the cleaning web sheet, a swing cam rotationally driven by the rotation drive portion, a rotation transmission portion that transmits a rotation drive force to the cleaning web sheet roller, a one way clutch provided on an input shaft of the rotation transmission portion, and a swing lever connected to the one way clutch and biased so as to be brought into slide contact with the swing cam.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2010-111392 filed in Japan on May 13, 2010, and Patent Application No. 2010-111394 filed in Japan on May 13, 2010, the entire contents of which are herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a fixing apparatus that fixes a toner image formed on a recording sheet and an image forming apparatus including the same.[0004]2. Description of the Related Art[0005]A fixing apparatus of this type is applied to an image forming apparatus that uses an electrophotographic method, an electrostatic recording method, a magnetic photographic method, or the like. Such a fixing apparatus heats and presses a recording sheet (such as plain paper, electrostatic recording paper, or photographic paper) onto which a toner image has been transferred, the recording sheet being sandwiched between a p...

AI Technical Summary

Benefits of technology

The present invention provides a fixing apparatus for an image forming apparatus that can rotate a take-up roller for a web sheet at a speed appropriate for the position of the shaft of the take-up roller and the shafts of the fixing rotation members, even if the positional relationship between the two changes. The apparatus includes a swing cam that causes a swing lever to swing, which is transmitted as an intermittent one-way rotation to a rotation drive portion, a one way clutch, a swing lever, a cleaning web sheet, and a rotation transmission portion. The apparatus can adjust the amount of web sheet taken up by the cleaning web sheet roller, and can switch between a pressing state and a pressure canceled state of the fixing rotation members. The apparatus provides a great speed reducing ratio and can stop the rotation of the cleaning web sheet roller when the position of the swing cam changes.

Problems solved by technology

Further, if the processing speed of the image forming apparatus is fast, and the number of sheets to be printed per unit time is large, smearing on the fixing rotation member of the fixing apparatus increases, and thus the smearing cannot be completely removed by cleaning the fixing rotation member using a blade or felt.

However, even if smearing on a fixing rotation member can be effectively removed by adopting cleaning using a web sheet, if a motor or a solenoid for rotating the web sheet take-up roller at a low speed is provided as with the case of the fixing apparatuses disclosed in Patent Documents 1 and 2, this results in an increase in power consumption and a rise of cost compared with using a blade or felt.

Thus, it was difficult to constitute a power transmission mechanism that can rotate both a fixing rotation member and the web sheet take-up roller using one motor, and can sufficiently increase the speed reduction ratio of the web sheet take-up roller.

Further, in the case where the motor for rotating a fixing rotation member is used as a motor for rotating the web sheet take-up roller, it was difficult to adjust the amount by which the web sheet is taken up since the fixing rotation members and the web sheet take-up roller are caused to operate in conjunction with each other.

For example, if the process speed is switched and set according to a color image or a monochrome image, the amount by which the web sheet is taken up also changed, and thus the take-up amount was not able to be accurately set.

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